Despite the presence of thousands of American troops in Iraq, President Barack Obama has ordered the deployment of 350 more US troops to the country.

"The president authorized the Department of Defense to fulfill a Department of State request for approximately 350 additional US military personnel to protect our diplomatic facilities and personnel in Baghdad, Iraq," a White House statement said on Tuesday.

"We will (also) continue to support the government of Iraq's efforts to counter ISIL, which poses a threat not only to Iraq, but to the broader Middle East and US personnel and interests in the region," it added.

The announcement was made hours after a video emerged showing the ISIL terrorist group beheading an American journalist, the second beheading in two weeks by the militants.

On Tuesday, ISIL released the video of the decapitation of Steven Sotloff, who disappeared in Syria in 2013. In a message, the journalist said that he is "paying the price" for US military intervention.

On August 20, the White House confirmed the authenticity of a gruesome video showing the beheading of US journalist James Foley.

Meanwhile, top US officials, including Secretary of State John Kerry and Defense Secretary Chuck Hagel, are traveling to the Middle East.

President Obama is being criticized by members of Congress over how he is dealing with the ISIL terrorists. Some members of the House of Representatives and the Senate said Obama has not done enough to combat the Takfiri group.

ISIL controls large parts of Syria's northern territory. The group sent its fighters into neighboring Iraq in June, quickly seizing large swaths of land straddling the border between the two countries.

The US military has begun planning for airstrikes against ISIL targets in Syria after the beheading of Foley. The US has launched a limited air campaign against the terrorist group in Iraq since August 8.